package com.application.vivi.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Stack;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;

import com.application.vivi.R;

public class ImageLoader {

	private HashMap<String, Bitmap> cache=new HashMap<String, Bitmap>();
	private File cacheDir;
	Context context;

	public ImageLoader(Context context)
	{
		this.context = context;

		photoLoaderThread.setPriority(Thread.NORM_PRIORITY-1);

		if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
			cacheDir=new File(android.os.Environment.getExternalStorageDirectory(),context.getString(R.string.cache_dirname));
		else
			cacheDir=context.getCacheDir();

		if(!cacheDir.exists())
			cacheDir.mkdirs();
	}

	final int stub_id=R.drawable.icon;
	public void DisplayImage(String url, Activity activity, ImageView imageView)
	{
		if(cache.containsKey(url))
			imageView.setImageBitmap(cache.get(url));
		else
		{
			queuePhoto(url, activity, imageView);
			imageView.setImageResource(stub_id);
		}    
	}

	private void queuePhoto(String url, Activity activity, ImageView imageView)
	{
		photosQueue.Clean(imageView);
		PhotoToLoad p=new PhotoToLoad(url, imageView);
		synchronized(photosQueue.photosToLoad){
			photosQueue.photosToLoad.push(p);
			photosQueue.photosToLoad.notifyAll();
		}

		if(photoLoaderThread.getState()==Thread.State.NEW)
			photoLoaderThread.start();
	}

	private Bitmap getBitmap(String url) 
	{
		String filename=String.valueOf(url.hashCode());
		File f=new File(cacheDir, filename);

		Bitmap b = decodeFile(f);
		if(b!=null)
			return b;

		try {
			Bitmap bitmap=null;
			InputStream is=new URL(url).openStream();
			OutputStream os = new FileOutputStream(f);
			Utils.CopyStream(is, os);
			os.close();
			bitmap = decodeFile(f);
			return bitmap;
		}
		catch(MalformedURLException e)
		{
			Bitmap bookDefaultIcon = BitmapFactory.decodeResource(context.getResources(),
					R.drawable.icon);
			return bookDefaultIcon;
		}
		catch (Exception ex){
			ex.printStackTrace();
			return null;
		}
	}

	private Bitmap decodeFile(File f){
		try {
			BitmapFactory.Options o = new BitmapFactory.Options();
			o.inJustDecodeBounds = true;
			BitmapFactory.decodeStream(new FileInputStream(f),null,o);

			final int REQUIRED_SIZE=70;
			int width_tmp=o.outWidth, height_tmp=o.outHeight;
			int scale=1;
			while(true){
				if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
					break;
				width_tmp/=2;
				height_tmp/=2;
				scale++;
			}

			BitmapFactory.Options o2 = new BitmapFactory.Options();
			o2.inSampleSize=scale;
			return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
		} catch (FileNotFoundException e) {}
		return null;
	}

	private class PhotoToLoad
	{
		public String url;
		public ImageView imageView;
		public PhotoToLoad(String u, ImageView i){
			url=u; 
			imageView=i;
		}
	}

	PhotosQueue photosQueue=new PhotosQueue();

	public void stopThread()
	{
		photoLoaderThread.interrupt();
	}

	class PhotosQueue
	{
		private Stack<PhotoToLoad> photosToLoad=new Stack<PhotoToLoad>();

		public void Clean(ImageView image)
		{
			for(int j=0 ;j<photosToLoad.size();){
				if(photosToLoad.get(j).imageView==image)
					photosToLoad.remove(j);
				else
					++j;
			}
		}
	}

	class PhotosLoader extends Thread {
		public void run() {
			try {
				while(true)
				{
					if(photosQueue.photosToLoad.size()==0)
						synchronized(photosQueue.photosToLoad){
							photosQueue.photosToLoad.wait();
						}
					if(photosQueue.photosToLoad.size()!=0)
					{
						PhotoToLoad photoToLoad;
						synchronized(photosQueue.photosToLoad){
							photoToLoad=photosQueue.photosToLoad.pop();
						}
						Bitmap bmp=getBitmap(photoToLoad.url);
						cache.put(photoToLoad.url, bmp);
						if(((String)photoToLoad.imageView.getTag()).equals(photoToLoad.url)){
							BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad.imageView);
							Activity a=(Activity)photoToLoad.imageView.getContext();
							a.runOnUiThread(bd);
						}
					}
					if(Thread.interrupted())
						break;
				}
			} catch (InterruptedException e) {
			}
		}
	}

	PhotosLoader photoLoaderThread=new PhotosLoader();

	class BitmapDisplayer implements Runnable
	{
		Bitmap bitmap;
		ImageView imageView;
		public BitmapDisplayer(Bitmap b, ImageView i){bitmap=b;imageView=i;}
		public void run()
		{
			if(bitmap!=null)
				imageView.setImageBitmap(bitmap);
			else
				imageView.setImageResource(stub_id);
		}
	}

	public void clearCache() {
		cache.clear();

		File[] files=cacheDir.listFiles();
		for(File f:files)
			f.delete();
	}

}
